Endoscopic surgical techniques have become widely accepted. As used herein, the term "endoscopic" pertains generally to the use of a surgical instrument which is inserted into a body cavity in conjunction with an endoscope which is inserted into the same body cavity. The endoscope permits visual inspection, with or without magnification, of the interior of the body cavity and permits observation of the operation of the surgical instrument for therapeutic or diagnostic purposes.
In a typical endoscopic surgical procedure, the abdominal cavity of a human or animal subject is insufflated with a sterile gas, such as carbon dioxide, in order to provide increased maneuvering room within the body cavity for endoscopic instruments. Then, conventional trocars are inserted into the subject's body cavity through the surrounding skin, tissue, and musculature. A conventional trocar typically consists of a trocar cannula which houses an elongated trocar obturator. Trocar obturators typically have a piercing point, although other types of obturators are also available.
After each trocar has been positioned within the body cavity adjacent the target surgical site, the trocar obturator is removed leaving the trocar cannula as a pathway to the body cavity. A plurality of trocar cannulas are typically placed in this manner. The surgeon can then insert an endoscope through one of the trocar cannulas and can insert various types of endoscopic, surgical instruments through one or more of the other trocar cannulas at the target surgical site where the diagnostic or therapeutic surgical procedure is performed.
The endoscope is typically connected to a video camera, and the output from the video camera is fed to a video monitor which displays the surgical site and the end of the endoscopic instrument at the surgical site. Examples of endoscopic instruments include ligating clip appliers, tissue cutters, electrosurgical instruments, tissue graspers, needle graspers, cannulas, tissue manipulators, and the like.
Although endoscopic surgical procedures offer many advantages, there are some problems associated with these procedures as conventionally practiced. For example, because the surgeon typically views the display on the video monitor as he manipulates instruments within the body cavity, the video display provides the surgeon with only a two-dimensional view of the surgical site, and there is a consequent loss of depth perception.
Another problem relates to engaging tissue from the instrument insertion direction. Many conventional, endoscopic instruments, such as graspers and scissors include a distal end mechanism for engaging the tissue in a way that effects the desired result (e.g., squeezing or cutting the tissue). Such distal end mechanisms can be generally described as "end effectors." In many conventional, endoscopic instruments, the end effector is mounted to, and extends generally linearly with, a rigid, straight shaft of the instrument.
Depending upon the nature of the operation to be performed on the tissue within the body cavity, it may be desirable to provide an end effector which can be angled or articulated relative to the longitudinal axis of the instrument shaft. This can permit the surgeon to more easily engage the tissue in some situations.
A further problem relates to the potential for blocking part of the field of view with the endoscopic instrument. Thus, the use of an endoscopic instrument with an articulating distal end would permit the surgeon to engage the tissue with the distal end of the end effector laterally offset relative to the instrument's main shaft. This would permit the engaged tissue and distal end of the end effector to be better viewed through an adjacent endoscope with little or not interference from the main shaft.
Although a number of designs have been proposed for articulating endoscopic instruments, and although articulating endoscopes and other instruments are commercially available, it would be desirable to provide an improved design for accommodating articulation of an end effector.
In particular, it would be advantageous to provide an articulating instrument with the capability for orienting the end effector at a substantial oblique angle relative to the longitudinal axis of the instrument. Further, it would be beneficial if such an improved design permitted articulation in any radial direction around the longitudinal axis of the instrument.
In endoscopic surgery it may be desirable in some situations to sense environmental characteristics at the surgical site (e.g., temperature, chemical, etc.). Further, it may be desirable to sense the actual presence or position of a component of the instrument. In addition, it may be beneficial to provide conduits for irrigation or aspiration at the surgical site. It may also be necessary to provide clips or staples at the site and to provide means, as part of the end effector, for applying the clips or staples. Accordingly, it would be especially advantageous to provide an improved articulable assembly which can accommodate internal sensor lines, aspiration conduits, irrigation conduits, flexible actuator members, as well as the feeding and application of fasteners (e.g., of clips and staples). Such an improved articulable assembly should preferably have sufficient interior space to accommodate internal passages and components and to permit the movement of such components through the articulable assembly.
It would also be advantageous if such an improved articulable assembly for an endoscopic instrument could be provided with a relatively smooth exterior configuration having a minimum of indentations and projections that might serve as sites for contaminants and be hard to clean or that might be more likely to catch on, or tear, adjacent tissue.
It would also be beneficial if such an improved articulable assembly could be provided with sufficient strength to accommodate relatively high moments and forces during operation of the instrument end effector in an articulated orientation as well as in a straight orientation.
An improved articulable assembly should desirably also permit relatively precise control of the orientation of the end effector relative to the longitudinal axis of the instrument. Further, it would be beneficial if such control could be exercised with a minimal amount of required input force or torque. Additionally, such an improved articulable assembly should easily accommodate operation and control from the proximal end of the instrument exterior of the body cavity.
Also, it would be desirable to provide a system for transporting fasteners, such as ligating clips or staples, through the articulable assembly. Such a system should accommodate movement of the fasteners when the end effector is articulated, as well as when the end effector is aligned with the instrument main shaft. Further, such a fastener transport system should desirably isolate the fasteners within the assembly from adjacent mechanisms so as to avoid interference with the fasteners and/or contamination thereof.
The present invention provides an improved articulable assembly for an instrument used in an endoscopic procedure which can accommodate designs having the above-discussed benefits and features.